In its 19th century heyday, the city of Springfield in Massachusetts produced the first industrial assembly line, the first gasoline-powered automobile and the first sleeping rail car. Wason, one of its leading companies, made passenger coaches and streetcars for clients across the US and countries as far afield as Egypt. While Wason went out of business in the 1930s, Springfield prospered well into the 20th century before deindustrialisation forced many of its factories to close.

So when a Chinese company announced in 2014 that it was investing $95m in a new plant to build rail cars — on a site that once housed a vast Westinghouse factory that closed in the 1970s — many in the region were excited about the prospects. For the past four years, around 200 workers have been employed in a gleaming new factory producing cars for the Boston subway system, with work on similar contracts for Philadelphia and Los Angeles to follow. 

Yet rather than being celebrated as a symbol of potential regeneration, the plant has found itself sucked into the escalating  trade conflict  between the US and China.